For years natural turf surfaces were used for most outdoor sports, for example, soccer, football, field hockey, cricket, rugby, etc. Natural turf surfaces are surfaces constructed with a grass grown in soil, or some other surface layer of growth medium (e.g., sand and organic mixes, etc.), that is constructed upon a suitable foundation. A natural turf surface is generally preferred for its comfort, feel, grip, and appearance.
However, under heavy use and/or poor weather conditions, natural turf surfaces deteriorate rapidly and maintenance is costly. Intense activity on the turf destroys the grass and its root system, leaving mud and/or dirt on the playing surface. Prior to re-establishment of the turf, the surface is unsightly and often pockmarked, uneven, and possibly hazardous to use.
Another problem associated with natural turf surfaces is the use of painted-on yardage and boundary lines. Typically, such boundary lines are formed by painting the playing surface. For aesthetic reasons, such lines are generally painted just prior to each official game played on the playing surface. The repeated application of paint to the surface of the playing surface tends to kill the grass that is located under the painted surface. In addition, over time the multiple layers of paint build up, forming a surface that is substantially harder than the surrounding natural grass playing surface. Thus, the painted areas of the playing surface can create slippery spots within the playing surface, possibly leading to slips and falls by athletes using the playing surface. In addition, the painted areas can increase the possibility of injury to the athlete and create hard spots that can be uncomfortable or painful to an athlete who falls upon the painted area.
Due to the needs of sports programs, even after destruction of portions of the turf, play usually continues on the playing surface, even when the surface is badly damaged, until the sport's season is over, when the turf can be reestablished. Thus, the playing conditions on the playing surface continually decline over the season. At the end of the season, the natural turf surfaces are reseeded, the divots leveled and filled, etc. The natural turf surfaces are not usable during this reestablishment period because use defeats the reestablishment of the turf. The reestablishment period typically takes at least four months, or longer, under ideal weather conditions, during which the natural turf surface should not be used.
Recently, synthetic surfaces have been used as an alternative to natural turf surfaces. Synthetic surfaces generally come in two types, i.e., conventional and sand filled. Conventional synthetic is a dense synthetic material that has the appearance of dense grass blades. Sand-filled synthetic is a synthetic material similar to conventional synthetic turf, but with greater spacing between the blades, to accommodate a silica sand filling.
Both the conventional and sand-filled synthetics are placed indoors or outdoors, upon a foundation that may include an asphalt, concrete, wood, or other supporting subsurface along with cushioning mats, water drainage, and water irrigation.
Although synthetic turf surfaces are more durable than well-established natural turf surfaces, they are only moderately successful for sports and other uses. The most notable disadvantages of synthetic turf surfaces are the discomfort for the players and an increased number of injuries. Additionally, synthetic turf surfaces are generally expensive to put in place and have a life expectancy of 8 to 15 years, if properly maintained, and less if poorly maintained. Outdoor synthetic turf surfaces also remove large areas from the ecosystem, reducing natural processes including ground water recharge, oxygen and carbon monoxide balance, temperature modulation, and dust filtration. For these and other reasons, a number of synthetic turf surfaces are currently being converted back to natural turf surfaces.
As can be seen from the above discussion, there exists a need for an improved surface for sports and other uses, and a method of making the improved surface, wherein the surface provides improved comfort and fewer injuries to the users, while being durable under heavy use and in poor weather conditions. The present invention is directed to fulfilling this need.